Disclosed is a wireless communication terminal device that is capable of preventing inter-coding interference upon each of a plurality of base stations, even when the timing changes for a transmission of a control signal that is CoMP received by the plurality of base stations. Upon the device, a diffusion unit (214) employs any of a plurality of ZAC series that are reciprocally splittable with a reciprocally variable cyclical shift quantity to diffuse a response signal, according to an instruction from a control unit (209), and the control unit (209) controls, according to a difference between a timing of a transmission of a response signal at a first time and a timing of a transmission of a response signal at a second time that is later than the first time, the cyclical shift quantity of the ZAC series that is employed by the diffusion unit (214) at the second time.